1. Field of the Invention
The present invention relates to a method and an apparatus for controlling reactions that take place between carbon soot molecules, metal porphyrin complexes, metal phthalocyanin complexes and various gases or fluids, more particularly to a method and an apparatus for preparing active oxygen, which is considered to have satisfactory ability of decomposing harmful substances, such as inorganic compounds and organic substance, by making use of a gas containing oxygen as the gas to be allowed to react.
More particularly, the present invention relates to a method and an apparatus for decomposing harmful substances in a harmful gas or a solution by causing the harmful gas or the solution containing the harmful substances to react with active oxygen obtained from carbon soot molecules, metal porphyrin complexes or metal phthalocyanin complexes or by direct contact reactions with the foregoing molecules. In particular, the present invention relates to a method and an apparatus capable of purifying contamination substances in air or water. Therefore, the present invention relates to a technology for purifying environmental contamination which raises a problem in recent years.
2. Description of the Related Art
There have been a variety of conventional technologies for decomposing harmful substances by making use of active oxygen. A technology for decomposing organic compounds by utilizing ozone generated by an ozonizer has been available.
FIG. 10 is a schematic view which illustrates the structure of voice-less discharge ozonizer reported by Masaaki Tanaka and Norikazu Tabata in Magazine of Society of Electrostatics, Vol. 3, No. 3 (1983). Referring to FIG. 10, AC high voltage sources 4 are connected to metal electrodes 3. A glass plate 5 is disposed on either side of the metal electrode 3. Thus, ozonized gas is generated from a raw material gas 1.
An ozone generating mechanism of the ozonizer will now be described. When AC voltage of 6 to 18 kV is applied while causing a gas containing oxygen to flow between metal electrodes 3 that interpose the dielectric substance, such as glass or ceramics, voice-less discharge takes place. Electrons discharged from the electrodes collide with oxygen molecules so that excited oxygen molecules are generated. The excited oxygen molecules thus-generated react with other oxygen molecules so that ozone is generated. The ozone thus-generated is caused to react with organic substances to decompose the organic substances.
Another technology for decomposing the harmful substances by making use of direct reactions in place of using active oxygen is exemplified by sewage/waste water treatment technology typified by an activated sludge process, which is the application of the metabolic function of an organism, and a technology for decomposing the waste gas from the combustion unit, such as the engine of an automobile, by making use of a catalyst.
Investigations have been made to use metal or a metal oxide or metal ion exchanging zeolite in the technology for decomposing the waste gas using the catalyst. As reported by Masakazu Iwamoto in J. Chem. Coc., Faraday Trans. I, vol. 77 (1981), NO can be decomposed at a decomposing efficiency of about 90% if a copper ion exchanging zeolite is used as the catalyst and 4% NO is caused to react at 500.degree. C.
Although the technology for decomposing the harmful substances using generated ozone is effective, the types of the harmful substances, which can be decomposed, are limited because of the reactivity of ozone. For example, it has been known that acetic acid cannot easily be decomposed by ozone. What is worse, the arrangement that ozone is generated by a high-voltage discharge technology encounters a problem that energy cannot be saved and the size of the apparatus cannot be reduced. Further, ozone is stable for tens of hours after it has been generated and the human body is sometimes affected adversely.
The biological treatment technology using the activated sludge has various problems that a large-scale processing facility is needed, time to complete the treatment is too long and organisms are left in the form of sludge.
The decomposition of the waste gas using the catalyst encounters a problem in that the decomposing reactions do not proceed if the temperature is lower than a predetermined level.